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From May through July we typically see quite a few dead fish in the shallow waters around our large lakes and along the Lake Washington Ship Canal.

These small fish are typically minnow-sized sticklebacks or yellow perch, and the die-off is a natural phenomenon that occurs annually. The die-off is not the result of a toxic spill or other water quality problem.

May through July is the spawning season for many fish species in the lake, which is a stressful time for male and female fish that often results in the death of some individuals after the spawning period. Most of the dead fish found are males, as they expend a lot of energy in attracting the females, building the nest, and caring for the young. Fish that die after spawning are often washed up, and can be found in concentrated groups in shallow waters and on our beaches. In the Lake Washington system, many sticklebacks live for just one year, but in other places around the country they may live 2-3 years.